Breech bolt mechanism for repeating rifles



April 12, 1960 A. M. HuGHl-:L ETAL 2,932,108

BREECH BOLT MECHANISM FOR REPEATING RIFLES Filed May 21, 195e 2 sheets-sheet 1 m2 .M NNH E EAG dw vnu r MWH Cim Nw April 12, 1960 A. M. HUGHEL ETAI- BREECH BOLT MECHANISM FOR REPEATING RIFLEs Filed May 2l, 1956 n mma Mw H w h s M 2 m V L nn JOHN C.

ww b R @uw N IIJ i Y RMN &\ Nw Sv bv w Alvin M. Hughel, Monroe, and John C. Buchanan, Seattle, Wash.

Application May 21, 1956, Serial No. 585,994

2 Claims. (Cl. 42-18) This invention relates to repeating ries and it has referencemore particularly to an improved automatic reloading mechanism for repeating rilies with semi-automatic action; it being the primary object of the invention to provide a novel and improved automatic reloading action that is substantially shorter in comparison to actions now in use; that is powered for reloading by the force of expanding gases momentarily .conined in the barrel upon ring; that operates to cock the hammer mechanism readyw for ftiring incident to the ejection of the empty shell, ,and which embodies novel parts in the firing means thateliminates accidental firing of a shell while the` breech block or bolt `is not fully closed and locked. v

It is also an object of the invention to provide an automatic reloading action that comprises relatively few parts; that is comparatively simple in construction and mode of operation, and free of parts that are apt to become out of working order after once being assembled.

Further objects and advantages of the invention reside in the details of construction and combination of the various parts and their mode of operation, as will hereinafter be fully described.

In accomplishing the above mentionedand other objects of the invention, we have provided the improved .details of construction, the preferred forms of which .are illustrated in the accompanying drawings, wherein:

Fig. l is a longitudinal sectional view of a portion of a repeating rifle showing it as equipped with the automatic reloading mechanism embodied by the present invention.

Fig. 2 is a substantially horizontal section of the riile takenin the axial plane ofthe bore of the barrel and breech block. Y t l Fig. 3 is a perspective view, showing the actuator rod and the means for its functional actuation.

Fig. 4 is a somewhat enlarged vertical section of the present action, showing the bolt fully retracted and the hammer latched in itsl cocked position.

Fig. 5 is a perspective. view of the bolt actuator bar guide frame as removed from thestock.

Fig. 6 is a perspective of the block which constitutes the major part of the receiver, and which is herein referred to asthereceiver block, with a part broken away for better illustration of inside detail.

Fig. 7 is a vertical cross-section of the receiver taken online 7-7 in Fig. 6.

Fig. 8 is a perspective view of the breech bolt.

Referring more in detail to the drawings:

In Fig. 1, we have shown, in' `longitudinal section, a rie which has been equipped withV automatic reloading mechanism embodied by the present invention; parts being broken away to shorten the view.

In this view, the receiver is shown in the form of a single block, designated in its entirety by reference numeral 10. Threaded into this block, at its forward end, is the gun barrel-1 1, designed in the usual way to receive a cartridge, suchasshown at 12. Fixed to the receiver 10, at its rear endgis the usual gun stock 13; this being A shown best in Figs. 4 and 8.

2,932,15053 Patented Apr. 12, 1959 lice attached to the receiver by means of upper and lower tangs, 14 and 15. The stock also includes a forward hand grip portion 16, as shown, which extends for substantial length forwardly along the barrel.

The receiver 10 is longitudinally bored, coaxial of the barrel as will be understood by reference to its showing apart from the rie yin Fig. 7; being formed below the bore with a chamber 17 that opens to the underside of the receiver to receive the discharge end portion of a shell clip 18 therein, as seen in Fig. 4, and is open at its rear end for direct communication with a stock chamber containing a guide frame designated in its entirety by numeral 19, and the trigger mechanism, as will presently be fully explained; the guide frame being shown removed from the stock chamber in Fig. 5,

The bolt 20 is of the form and detailed construction It comprises a relatively short cylindrical body slidably contained in the longitudinal bore of the receiver and adapted to be locked in its closed position with its forward end atly against the inner end of the barrel andbase end of the cartridge 12, as seen in Fig. l. When unlocked, it is reciprocally movable in the receiver bore. In order to lock it in its closed position, as in Fig. 1, Vit is formed on opposite sides with projecting lugs 21 and 22, that are slidably contained in channels 23 and 24 that extend horizontally, and longitudinally along the inside wall surfaces of the bore in the receiver 10, and which channels at their forward ends are directed circumferentially, as seen at 23x and 24x in Figs. 4 and 7. When the bolt 20 is moved forwardly and the lugsthereon are caused by the slight turning thereof to enter these circumferentially directed portions ZSxvan'd 24x of 4the channels, the bolt will be moved tightly against the barrel and the base of the shell 12 as in Fig. l, and at the same time will be locked against retraction or recoil. To release the bolt for its retraction, it is rotated in a reverse direction, or counter-clockwise in reference to its showing in Fig. 7, about 30, and moved rearwardly.

The means for automatically retracting the bolt 20 may be the conventional form of gas pressure means which is shown in Fig. 3 to comprise a piston rod 25 reciprocally iitted in a cylindrical tube 26 that is fixed to and which extends along the underside of the barrel 11; being confined in the forward portion 16 of the gun stock, as in Fig. l. At its forward end, the tube 26 is closed, but adjacent the closed end it has a gas passage 27 opening therefrom and into the barrel bore 11b as shown in Fig. 3. Gas under pressure confined momentarily in the barrel back of the tired bullet, will be applied through port 27 to the piston rod and will drive it rearwardly. The rod transmits rearward .movement to an extension orV actuator bar 28 that extends along the barrel to the breech bolt 20. The rearward end portion of this bar is movable in a slot 29 in a wall of chamber 17 of the frame block, and at its end it mounts an inwardly directed stud 30 which at its inner end is contained in a spirally directed cam groove 32V in the adjacent side surface of the breech bolt 20, asV indicated in Fig. 3. When the parts are in normal position, ready for firing, they assume the relationship in which they are shown in Figs. 1, 2 and 3. However, when a cartridge is fired, the barrel gas pressure acts against the piston rod 25 to drive the actuator bar 28 rearwardly. This causes the stud 30 to so act on the sidewall of the cam slot as to rotate the bolt 20 in such direction and extend as to unlock it, and permit it then, under the driving #force of the piston rod 25, to be moved rearwardly, as to the retracted position in which it is shown in Fig. 4.` y

`When the gas pressure acting againstthe piston rod is dissipated, the actuator rodandbar are returned to normal position by the force of a coiled spring 33 acting thereagainst.

The rearward movement of the breech bolt incidentally extracts the lired shell into the frame chamber 17 from which itis laterally discharged through the sidewall opening shown at 35 in Figs. 2, 6 and 7. lThe means for shell' extraction comprises a spring clip 36 carried on the bolt 20 at one sideat its forward end; this clip having an inturned ange 36' thereof adapted to be disposed beneath the rim of the cartridge shell as it is seated for tiringv in the barrel bore. Thus, when the bolt is pulled rearwardly, the clip extracts the shell from the barrel.

By reference to Fig. 8, it will be observed that thev rear end of the breech bolt 20 is formed with a coaxial cylindrical hub or extension 40 of reduced diameter, about which a collar 41 is fitted for relative rotation; the collar being locked against removal from the hub by lugs 42 and 42 that project radially from the extension portion. The collar is provided with key ways 43 through which the lugs may be passed for the assemblyy of these parts, then, by rotation of the collar to its normal position, the key ways are moved out of alignmentv with the lugs. These parts are assembled before being placed in the receiver, and after being functionally positioned therein they cannot rotate relative to each other to the extent necessary to become disconnected.

Projecting rearwardly from the collar 41, at diametrically opposite sides thereof, are ears 44-.44 and between these ears the forward end of a guide bar 45 is pivotally fixed by pins 47'. When the parts are in the normal position, as shown in Fig 1, the bar 45 is contained almost in its entirety in the receiver bore, with its rear end portion extended into the forward end'portion of the guide frame 19 which isset within the forward end of the gun stock 13. The frame 19 is of the form of construction vshown in Fig. S. It comprises laterally spaced side plates 19a and 19b secured in spaced relationship across their top edges by cross-bars 19x, and at their lower edges by a box-like frame 192. This guide frame is rigidly secured in the stock by its connection to the top tang 14 and an anchor bolt applied through the box frame and secured in the stock 13.

The spaced plates of the guide are formedA lengthwise with coextensive slots 48-48 in which the opposite end portions of a pin 49, applied through the rear end of bar 45, are contained. Thus, when the breech bolt 20 is unlocked and actuated rearwardly, the collar member 41, moving therewith, is held against anyl relative rotary movement in the receiver.

A tiring pin 50 is contained in the breech bolt 20 in a bore that is so directed longitudinally through the bolt that it places its striking end eccentric of the block axis. Thus, when the bolt is in closed and locked position, the striking end of the pin projects therefrom slightly below its axial center. A tiring pin striker rod 55 is contained in a bore formed lengthwise in the bar 45 as noted in Fig. l. In the normal position of these parts, as shown in Fig. l, the striker rod 55 is aligned axially with the ring pin 50 and when it is struck at its outer end by the hammer, as presently explained, it functionally actuates the firing pin. However, whenever the breech bolt is not in its fully closed and locked position, the tiring pin, as contained therein, will be out of lin'e with the striker rod and the cartridge cannot be fired by any accidental hammer action.

It will be noted by reference to Fig. 1, that the `bar 45 is recessed ork cut away along the underside of its rear end portion, thus providing it with an inclined rearwardly facing shoulder 57 through which the rearward end of the striker pin extends from the bar. When the parts are in the normal position, as in Fig. l, the striker pin 55 is in position to be struck by the hammer for fir,- ing the cartridge. The hammer mechanism will now be described.

The hammer mechanism, as shown Iinl'ig. 4, is in its cocked, ready-to-re position as set by the rearward actuation of the bolt and bar 45. It comprises the hammer plate 60, set in the vertical a-xial plane of the receiver with its lower end portion disposed between laterally spaced llanges 61-61 formed on and along the top side of the lower tang 15. A pivot pin 62 through the flanges and lower end of the plate, permits the hammer to swing between its full line and dotted line positions asY seen in Fig. 4.

In Fig. 1, the hammer is ,shown after being released by the trigger action and at the instant it is striking the striker rod 55 for firing the cartridge, it is then in a position of rest at, which it will be acted on at its upper forward corner by the shoulder 57 of bar 45 as the breech bolt 20 and bar 45 are driven backA by action of the ejector rod 25. When the hammer reaches its rearward position, as in Fig. 4, it is latched there by a pawl 70 mounted on a pivot pin 71 between the flanges 61-61. A, leaf spring 72, mounted on thel tang 15, bears upwardly against the pawl to urge it to hammer latching position.

The hammer is released for firing by the pulling of a trigger 74 that is pivotally mounted by pivot pin 75 between the tang anges 61-61. The trigger extends downwardly through tang opening 76 in the usual way. At its upper end, a pawl 77 is pivoted thereon by a pivot pin 78. The pawl engages at its end with a notch 77 in the top edge of the hub portion ofV sear 70; being yielding urged to that position by a small coil spring 80 carried on a rearward projection at the upper end of the trigger. When the trigger is pulled, the pawl 77 eects release of sear 70 from the hammer. The hammer is then driven forciblyagainst the striker rod 55 to re the cartridge; being powered by a coiled spring 81 mounted under compression on a rod 82 that is telescopically mounted in a carrier 83, pivoted on the guide frame part 19z. The rod moves in and out of the guide with the action of the hammer.

Assuming the parts to be so constructed, and assembled as described, the functioning of the present action is as. follows:

Starting with the parts in position of Fig. 1 which shows the hammer released and at the instant it strikes the rear end of the striker rod 55. This causes the rod 55 to transmit the hammer blow to the firing pin 50 to fire the cartridge. With the explosion of the cartridge, gas confined back of and driving the. bullet, is forced through thepassage 277 into cylinder 26 tol drive the piston rod 25 and actuator bar rearwardly. The stud 30 on the bar, through its cammingl action on the side wall of the spiral channel 32 of the breech bolt, rotates the bolt in such manner as to release it for rearward action. Then the bolt is driven rearwardly, pushing the guide bar 45 back into the guideway 19. As the bar moves rearward, its shoulder 47 acts on the hammer to move it back to its Fig. 2 position in which it is latched bythe sear 70. With the dissipation of the gas pressure in the barrel, the actuator bar is returned by the coiled spring to its normal forward position. In moving for- Ward, the rod pulls the breech bolt back to its starting position, and then causes it to be turned and locked i. closed position, l

When the breech bolt 20 is driven rearwardly, the tired shell is automatically extracted from the barrel and ejected, being pulled from the barrel by the .spring clip 65 attached vto the bolt. .As the bolt reaches, its fully retracted position, as in Fig. 4, au ejectorpin SAQ mounted slidably therein and extending from the ends ofthe bolt, engages at its Vrear end with a forwardly farcing shoulder 92 at the rear of the receiver, thus V,pushing the pin forwardly, causing its vforward end to'engage. theedge of the shell base, opposite the `part held by the. extractor clip, thus to ip the empty shell laterally'from the'receiver chamber through the sidewall opening. With the ejection of the empty shell, a loaded cartridge is allacaaios tomatically fed from the clip 18 into the chamber 17, then as the breech bolt is actuated forward, it forces this cartridge into the barrel. As it moves into position, thel rim ange of the base end is caught beneath the extractor flange and the block closes against the shell as in Fig. 1.

What We claim is:

l. In a rie ofthe character described; a receive formed with a longitudinal bore, a guide frame located immediately rearward of said bore, a breech bolt reciprocally mounted in said bore, means for effecting reciprocal movements of said bolt between open and closed position; said bolt having a length that is substantially less than its reciprocal travel in moving between open and closed positions and having lugs projecting from sides thereof; said bore having channels formed lengthwise thereof in which said lugs are slidably contained for the guided travel of the bolt and which channels have forward end terminal portions curved circumferentially of the bore and into which said lugs will move to lock the bolt when actuated to its closed position, a collar rotatably tixed about the rear end portion of the bolt, a guide bar connected at its forward end to said collar for reciprocal movement in said guide frame, a tiring pin extended eccentrically from the rear end of said bolt and a pin striker rod contained in said bar with which y 6 the tiring pin is brought into coacting alignment by movement of the bolt to closed and locked position.

2. The combination recited in claim 1 wherein said guide bar has a swivel connection at its forward end with lthe rear end of said bolt and a non-rotating sliding connection at its rear end with said guide frame, and said striker rod extends from the rearward end portion of the guide bar for engagement by a hammer for tiring when the bolt is closed.

References Cited in the le of this patent UNITED STATES PATENTS 813,694 Fidjeland Feb. 27, 1906 1,376,694 Hines May 3, 1921 2,035,539 Dicke Mar. 31, 1936 2,098,562 Browning Nov. 9, 1937 2,341,780 Horan Feb. 15, 1944 2,386,543 Collins Oct. 9, 1945 n 2,424,264 Yorks Iuly 22, 1947 2,484,694 Dicke Oct. 11, 1949 2,606,382 Schaich Aug. 12, 1952 2,606,383 Jensen Aug. 12, 1952 2,685,754 Crittendon et al. Aug. l0, 1954 2,742,822 Harvey Apr. 24, 1956 2,803,080 Simmons Aug. 20, 1957 

